i have a 2002 supercrew with a 4.6litre. not everytime but once in awhile my truck puffs blue smoke on start up. the truck has only 28000kms on it . does anybody no what this could be or had this happen to them . are my valve seals going ??i hope this isnt a major problem. and no my truck isnt abused at all , this truck is my baby so this is why im wondering whats up?? thank for the help if possible

 

Mine does the same thing. Bought in new in 2000 and at 4000 Km it puffed blue for the first time.I couldnt believe it. Took it to different dealerships and did I get the BS. "wait until the motor breaks in" "Sorry, we cant find nothing wrong" Yada Yada Yada... I tried different oil filters and oil and still it puffs. It is embarassing when your neighbors buy GM and Dodge and theirs dont do it. Sorry, I cant help you.

 

PS. I forgot to mention that I have a 4.6 litre as well.

 

My father has a 2003 E350 w/ the 5.4. If it sits for more then a week it will give a puff. Runs great, doesn't burn oil, no leaks. I always wonder why it does it, but so far no problems.

 

Has all the symtoms of valve guide seals leaking.

First start up after sitting a while. Classic valve guide seals.

 

I also think oil might be dripping past the valve guide seals when the engine is shut off. You probably don't burn/use oil though.

 

no its does not burn any oil between oil changes. and yes it seems to do it when it sits for a little while. so you think its valve seal guides?? was this a problem on these trucks??

 

My truck does the same thing. Its doesn't smoke on a cold startup, but it throws a puff when I restart the truck after it ran for only a minute or two. Let me explain. If I go first thing in morning, start the truck it doesn't smoke. Now if I pull the truck out of the garage and turn it off before it warmed up, then I start it again and it smokes. My mechanic said its from not warming the truck up. I'm turing off a cold engine . Hope this makes sense. I'm just not going to worry about it. I've been told its nothing and it doesn't mean your engine is bad or burning oil.

 

The 4.6L in my work EconoLine did this frequently until the EGR valve was replaced.

 

My 99 did this once. I changed the PCV valve and it stopped. Its a cheap thing to try so give it a try.